nushell/crates/nu-cli/src/commands/compact.rs

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use crate::commands::WholeStreamCommand;
use crate::context::CommandRegistry;
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use crate::prelude::*;
use futures::stream::StreamExt;
use nu_errors::ShellError;
use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
use nu_source::Tagged;
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pub struct Compact;
#[derive(Deserialize)]
pub struct CompactArgs {
rest: Vec<Tagged<String>>,
}
impl WholeStreamCommand for Compact {
fn name(&self) -> &str {
"compact"
}
fn signature(&self) -> Signature {
Signature::build("compact").rest(SyntaxShape::Any, "the columns to compact from the table")
}
fn usage(&self) -> &str {
"Creates a table with non-empty rows"
}
fn run(
&self,
args: CommandArgs,
registry: &CommandRegistry,
) -> Result<OutputStream, ShellError> {
compact(args, registry)
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}
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fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Filter out all null entries in a list",
example: "echo [1 2 $null 3 $null $null] | compact target",
result: Some(vec![
UntaggedValue::int(1).into(),
UntaggedValue::int(2).into(),
UntaggedValue::int(3).into(),
]),
},
Example {
description: "Filter out all directory entries having no 'target'",
example: "ls -af | compact target",
result: None,
},
]
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}
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}
pub fn compact(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
let registry = registry.clone();
let stream = async_stream! {
let (CompactArgs { rest: columns }, mut input) = args.process(&registry).await?;
while let Some(item) = input.next().await {
if columns.is_empty() {
if !item.is_empty() {
yield ReturnSuccess::value(item);
}
} else {
match item {
Value {
value: UntaggedValue::Row(ref r),
..
} => if columns
.iter()
.all(|field| r.get_data(field).borrow().is_some()) {
yield ReturnSuccess::value(item);
}
_ => {},
}
};
}
};
Ok(stream.to_output_stream())
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}
#[cfg(test)]
mod tests {
use super::Compact;
#[test]
fn examples_work_as_expected() {
use crate::examples::test as test_examples;
test_examples(Compact {})
}
}